Help - Restore Files

Hi all. So google has let me down and I can't come across anyone who's got an answer, so I shall ask here.

Basically my situation is this. I installed the Windows 7 Ultimate 'test' or 'beta' version over a year ago. I've been running it smoothly (love it) without a hitch. Then, I get messages that my trial period is over and I need to buy the legit copy.
So, I do. I bought Windows Home Premium. (So, technically a downgrade?)

Anyways, before I installed, I did a system backup onto my external drive (F:\) and everything worked out ok. After that, I put in the new disk, and install Windows 7 Home Premium. No problems there. Then I go to "restore" my previous file that's located on my external hard drive, and suddenly my computer cannot find it.

I can open the drive directly, and there is a system restore file there (taking up legitatmet space [134 / 500GB] but it just keeps directing me to the screen that can't locate my drive.

I backed my computer up, knowing I'd be making the switch and that I had important stuff on it, and now I can't seem to get it back.

Please help!

Thanks kindly in advance.

Did you do a file backup using Windows Easy Transfer, or an image backup using Backup and Restore?

Backup and Restore.

Edit:

I should mention.. Windows was smart enough to make a windows.old folder on my computer so thankfully I haven't actually lost anything, and can now just pull from there. However, the issue now becomes merging that folder with the real Windows folder. There any special way of doing that?

Thanks!